UV Curing - A Simple Explanation

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UV Curing A Simple Explanation

Although the ability to cure adhesives and coatings using Utraviolet Technology has been around for decades, there are still a decent percentage of companies who haven’t yet evaluated this time saving and efficient process for their applications. Whether it is the “Hey, what we do has always worked just fine for us”, or the, “I really don’t understand how it works” reply, lets explore a simplified version of what UV curing is and how it can benefit just about any process.

That Simple Explanation:
Ultraviolet (UV) curing is a process that involves the use of UV light to cure or harden materials such as adhesives, coatings, and inks. The process works by exposing this material to high-intensity UV light, triggering a chemical reaction that causes the material to harden or cure very quickly. This makes a much faster process than traditional methods that typically require heat or air drying.

What is Needed for UV Curing?
1) UV Material: Whether you are bonding 2 pieces of plastic together, fixing a hole in a hearing aid or drying ink you need a special material designed for that application that can be cured using UV light. The material is mixed with a photoinitiator, which will react to the UV light and cause the material to harden and cure quickly. The photoinitiator is formulated to react best when exposed to a certain wavelength. 365nm is the most common wavelength, but other wavelengths are also used. Finding out which wavelength works best for your material is as simple as consulting the data sheet for that material. Sometimes the wavelength is given as a range, meaning you can cure that material using any wavelength in that range. An optical power requirement will also be found on the Data Sheet, which is the amount of UV power needed to cure the material. This specification is typically given in watts per square centimeter (W/cm2) or milliwatts per square centimeter (mW/cm2).

2) Dispensing Method: This is simply how you are going to dispense the UV material. This can be as simple as a hand held syringe or as complex as an automatic dispensing system using robotics or spray guns. Many methods are available, depending on desired throughput.

3) An Ultraviolet Light Curing Device: To complete the UV curing process an UV light source is needed to emit the proper wavelength and optical output power to cure the UV material used. UV devices are available in a wide variety of wavelengths, so make sure to choose the one that is right for your material. Some units are broad-spectrum systems, such as flood or splash cure units that utilize bulbs or lamps for curing, so they are a little more forgiving with the wavelength. Systems that cure with UV LEDs have a much tighter output wavelength spectrum, so it becomes more critical in choosing the proper output wavelength. A LED system emitting a peak wavelength of 365nm is going to have a very hard time curing material formulated to cure at 405nm due to the narrowness of the output spectrum, where a flood unit with a peak wavelength of 365nm would likely cure materials from 300-420nm, even though it would be most efficient at the peak wavelength of 365nm.

UV Light-curing systems are available in a number of different configurations for just about any application, including the most popular spot, flood, and conveyor systems. But, regardless of which system you choose the light curing unit needs to have enough optical output power to cure the material properly. Material that needs 100mW/cm2 to cure is going to take much longer to cure using a device that emits 25mW/cm2, and may not cure the material to satisfaction.

So, What are the Benefits?

- Speed is the most obvious benefit. UV materials cure in a fraction of time compared to traditional methods. Even compared to cyinacrolates or “super glue” as the curing process doesn’t start until the UV light actually engages the material, giving the user more control over the curing process.

- Convenience as UV materials are a one part formulation without a time to use compared to some materials, such as epoxies, that need to be mixed and can only be used in a certain time-frame after mixture.

- Performance as UV cured materials typically have better adherence to a wider variety of substrates compared to traditional materials.

As you can see, the UV curing process has many advantages over most traditional methods and can save a bundle of time in just about any application. If UV curing is new to you, or you want to discuss your application, contact us here: Contact

About the Author
Chris Perkins is the owner of Lightning Enterprises, and facilitates the Lightning Enterprises newsletter. He has worked in the hearing aid industry since 1991 in hearing aid manufacturing and product development, as well as equipment and process consulting.

Article Posted: 11/08/2023 06:31:34 PM